(1) Field of the Invention
The present invention relates to a metallizing composition. More particularly, the present invention relates to a metallizing composition comprising an oxynitride glass component, which is useful for forming a metallized layer on the surface of a nitride ceramic or carbide ceramic material.
(2) Description of the Prior Art
Bonding of a ceramic material and a metallic material is important in the industrial technique of producing composite products comprising these materials, and since the application field of ceramic bodies obtained by sintering nitrides and carbides such as Si.sub.3 N.sub.4 (silicon nitride), AlN (aluminum nitride) and SiC (silicon carbide) is now broadened because of their excellent high-temperature characteristics and high strength, the technique of bonding these ceramic bodies to metals attracts great attention in the art. Namely, a considerable strength is required for the bonding between a ceramic material and a metallic material, whether this bonding is electrical bonding or mechanical bonding.
Various metallizing methods have been heretofore adopted for this bonding, but these methods involve technical problems.
For example, the known high-temperature metal ceramic joining method, for example, Telefunken method is defective in that when a non-oxide ceramic material is used, bonding having a high strength cannot be obtained. The method for forming a thin metal film on a ceramic body by vacuum deposition is defective in that the applicable shape is limited and the cost is high. The method for casting a metallic material in a ceramic body is insufficient in that the use is restricted. Moreover, the method in which a material having a thermal expansion value intermediate between those of a ceramic body and a metallic material is interposed between them and the frictional welding method are still insufficient because the bonding strength is low and the shape formed by bonding is limited.